I have some thoughts on the whole parenting thing, regarding why a father and mother unit is not the be all, end all in parenting, and why other family units are just as valid.
Humans are inherently flawed. These flaws vary in scope and degree, but I think it's very safe to say that none of us are perfect, and we bring these imperfections into every aspect of our lives, including our parenting. For example, I have no doubt that Nathan and his spouse, who I'm guessing are a very traditional family, are great parents. I'm sure they treasure their children, keep them safe, teach them right and wrong according to their values, want the very best for them, and are doing all that's within their power to raise them to be fully functional and productive members of society. I'm sure his kids will probably turn out to be just that, people that he and his wife can be very, very proud of. But will they be perfect? I doubt that. They will have their flaws, just like the rest of us.
To get a little more specific, I (imperfect me) have raised my daughter as a single parent for over 10 years now, and she's now university-aged. During that time, her father has been an inconsistent figure in her life. Is she lacking because of the absence of a present, engaged father figure? Has this caused her to be flawed in any way? Probably. But on the other hand, she has so many amazing qualities, and some of them have come because of being raised by a single parent. So, if she'd had a present father for all these years, she may have gained in some areas, but she also would have lacked in others. She would still be flawed, but she would be flawed differently. Further, I contend that in whatever criteria make a person a good one, she would easily hold her own against or even surpass children raised in the best and most functional of two parent, opposite gender families. I deeply resent the implication I've seen many times in various parenting threads here that single parenthood is inherently inferior to other family types.
The exact same thing can be said for homosexual families. Do they lack anything because of not having two different gendered parents? Probably at least a little. But what they do lack will be compensated for in other areas. Their flaws will be different, but not necessarily greater than the flaws of a child raised in a male - female headed family.
My point is, no one type of family unit can be said to be superior to another. It all depends on the individuals involved, and their commitment to parenting. One thing that can be said for a same sex headed family though, is that given the hoops they must jump through in order to have a child (as opposed to heterosexuals who can produce them with as little as a casual roll in the hay that was meant purely for sexual gratification), their children are probably far more intentional and wanted than many children born to heterosexual parents, and that has to be a positive thing.